And in the interest of balance for informed commenters, here is Lumagen's take on this from AVS:-
The Pro HDR IM output colors for the Mad Max sand storm explosions are correct based on the pixel data. The explosions are mostly burnt orange with some yellow, not the other way round. The data does not overflow the Pro HDR IM as we initially considered possible. A 1D LUT as used for the ARVE tool cannot process the Tone Mapping correctly since each color is independent and so color balance between R, G, and B will change when they are not supposed to, as in the explosion scene. I initially looked at a 1D LUT approach for IM and immediately tossed it as mathematically incorrect. Took all of 5 minutes to decide this.
NOTE: This is NOT a dig at the ARVE tool. It uses the hardware available in the projector (a 1D LUT) and does a pretty good job with what is available.
The term "illegal colors" is too strong. Rather colors should be "Protected for RGB" in the editing stage. This has been standard practice for many years. Not doing so means the colors change as one primary clips first due to how the color space conversion calculation works. Having YCbCr values that cause clipping in RGB is a big issue, but it is not an issue in the Mad Max sand storm scene (at least not for the Pro IM).
Saying one wants the explosions to look yellow when they are mostly burnt orange is like saying I want my grass to be pink. Maybe so, but no good way to make an exception in the math that does not also screw up other colors too. And you would of course be seeing the wrong color for grass. Does not make sense. Reminds me of people liking their whites to be blue because they got used to TVs in "torch mode."
Interesting side note: I checked the color verses temperature of a propane explosion. Going from hot to hotter you have yellow, then orange, and then red. So, the central part of the explosion being hotter should be burnt orange or orange, with the fingers of the explosion cooling to orange and yellow. In my opinion this is how it looks with the Radiance Pro HDR IM, and this matches the data on the disc.
I would be interested in seeing the sand storm scene on the Pulsar monitor it was edited on to confirm all this, but I am convinced it would confirm the Pro IM rendition of color.
There, I have created my own sandstorm.
After more deliberations.
Lumargen Pro work in progress.......
Lumagen:-
"We will be changing the HDR IM parameter defaults in the next release. These changes will affect only the defaults when the parameters are reset (in the HDR IM parameters menu, or a factory reset, plus a Save). We need to thank Kris Deering for his work testing the various permutations of Display Max Light, Tran and Shape to discover the optimal settings."